Genetic counseling: Cleft Palate - Pierre Robin Sequence-2
Pierre Robin Sequence Contracting *How have things been going since your last visit to genetics? *What questions or concerns would you like to discuss today? *Set agenda for session Etiology *Association of micrognathia, cleft palate, and glossoptosis *Multiple anomalies caused secondarily by a structural anomaly **Micrognathia or retrognathia at 9-11 weeks of embryonic development prevents tongue from descending from between palatal shelves **Tongue prevents palatal shelves from growing together horizontally and fusing **Causes tongue to be displaced, blocking airway *About 80% of cases may be caused by a multiple anomaly syndrome **34% of Pierre Robin due to Stickler syndrome **Due to mutations in COL2A1 gene usually at 12q13 **Also could be due to mutations in COL1A1 (1p21) or COL1A2 (6p21) **Autosomal dominant disorder with 50% recurrence risk **11% of Pierre Robin due to VCF **Deletion of 22q11 **Recurrence risk 50% if one parent has deletion **Many other single gene disorders, some X-linked recessive disorders, recessive disorders **Teratogenic exposure **Fetal alcohol syndrome **Fetal hydantion syndrome **Retinoic acid embryopathy *Isolated Pierre Robin sequence **May be due to fetal crowding due to presence of multiple fetuses, abnormal fetal position, uterine anomalies, or oligohydramnios **Associated deformities may also occur **Multifactorial inheritance **Recurrence risk if one child with cleft palate 3-5% **Recurrence risk if two children with cleft palate 10-12% **Affected individual has 3-5% chance of having a child with cleft palate *Incidence is about 1/2500 births for cleft palate Clinical Features and Natural History *Craniofacial **Often U-shaped cleft involving both hard and soft palate **Small and symmetrically receded mandible **May cause dental crowding **Jaw may "catch up" in adolescence if due to mechanical constraint **Flattened base of nose *Growth and Feeding difficulties (long-term feeding problems 50%) **Failure to thrive evident in neonatal period **Poor suck due to cleft palate **Inability to nurse, irritability, aspiration **Often due to respiratory difficulties *Respiratory complications **Upper airway obstruction often present at birth or shortly after **Deep pectus excavatum **Cyanosis not common but may occur **May be due to glossoptosis obstructing the epiglottis **Complications of continuing airway disorder may include sudden death, failure to thrive, persistent deformation of sternum, decreased pulmonary function, cognitive effects of hypoxia *Ears and Hearing **Middle ear disease due to cleft palate **Chronic ear infections may lead to conductive hearing loss *Cognitive and motor development normal in isolated Pierre Robin sequence Testing Options *Genetic testing may be offered if genetic syndrome is suspected **Chromosome analysis **FISH for deletion of 22q11 **DNA testing for mutations in collagen genes indicated in Stickler syndrome *Level II ultrasound prenatally at 18-20 weeks gestation for cleft palate but difficult to identify Management and Treatment *Overcoming feeding difficulties **Important that baby learns to actively suckle **Establish feeding routine that requires short feeding time **Use special cleft palate nursing bottle **Reflux may be treated with medication or regular breaks to burp **May require NG tube or g-tube *Cleft palate repaired surgically 9-18 months **Weight, size of airway are factors in when surgery performed **Must be sure lower jaw is wide enough to accommodate tongue once palate repaired **Usually requires 1-3 day hospital stay *Jaw distraction surgery now being performed on infants in some hospitals *Tracheostomy may e required if severe airway issues *Special services **Speech therapy to prevent speech and language delays **May require IEP from school or other services, particularly if caused by underlying genetic syndrome *Chronic middle ear infections treated aggressively with antibiotics or PE tubes to avoid conductive hearing loss, speech and language delays Differential Diagnosis *Most commonly associated with VCF or Stickler syndrome *Some other associated syndromes include Myotonic Dystrophy, Campomelic dysplasia, Lenz syndrome, Nager syndrome, Treacher Collins syndrome, and Turner syndrome Psychosocial *Frustration, impatience due to feeding difficulties in newborns *Difficulty relating to baby due to physical appearance, inability to breastfeed *Guilt, anxiety, depression, anger about diagnosis *Assess support system Resources *Pierre Robin Network :http://www.pierrerobin.org/ *American Cleft Palate-Craniofacial Association :http://www.cleft.com/ :800-242-5338 References *"Orofacial Clefting Syndromes: General Aspects." Syndromes of the Head and Neck (1990) 693-704. *"Pierre Robin Fact Sheet." Pierre Robin Network. http://www.pierrerobin.org/ *Shprintzen RJ. "Robin Sequence." Management of Genetic Syndromes (2001) 323-336. Notes The information in this outline was last updated in 2000. Material obtained under GFDL Licence from http://en.wikibooks.org/wiki/Handbook_of_Genetic_Counseling